JPH02181545A - Address control system for lan bridge - Google Patents

Abstract

PURPOSE:To facilitate the inspection of an address mistake by executing the rewriting of registration when a certain fixed time has passed at the time of outputting a registration request in the same work station address from another route, and inhibiting the registration when the fixed time has not passed. CONSTITUTION:The address of a work station(WS) which is not used for a long time is erased from each bridge address route table 25 by a timer 1. If the switching time is not a short period even when the WS connected to an LAN is switched to another LAN, the WS can be registered and used. If the WS is set up on the same address in error and simultaneously used, the same address may be registered by different routes at the bridge within a short time. However, the registration can be immediately rejected by monitoring a timer 24 and abnormality can be instantaneously detected.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an address management method for a bridge that connects local area networks (LANs) [Prior Art] Several methods have been shown as LAN bridge methods. However, there is still no example of how to deal with duplicate addresses, and problems have arisen in actual systems.

Currently, two workstations (WS) erase each other's route information, reducing the efficiency of the LAN. Since large-scale LANs have not yet been put into practical use in the world, they are not widely used.The bridge route management method is described in the IEICE technical research report (88).
-5-19) p43, rLAN standardization trends and issues".

[Problem to be solved by the invention]

When a LAN bridge receives a frame from a WS, no address is registered at the time of system startup, and it registers which route the sending WS address came from in the address route management table. The destination WS does not know which route to the LAN it is connected to, so it sends the frame to all routes.If the destination address route is already registered, it sends the frame only to that route. . Sending frames to all routes wastes the LAN transmission path, so if this happens frequently, it will degrade the LAN performance. If the registration rate is high.

LAN usage efficiency improves. However, the W of the entire LAN
Since the number of Ss expands infinitely, there is a physical limit to the bridge's ability to memorize all the WS routes.
It's impossible. Therefore, the table of addresses that are not used even after a certain period of time is deleted, making it easier to register other addresses. Furthermore, even if a WS is once registered, the WS may be moved due to business reasons, and the same WS may be connected to a different route from a certain point onwards. To solve this problem, if a WS route that has already been registered even if a certain period of time has not passed, if there is a registration request from another route, the previous route will be allowed to be rewritten with a new route. ing. Therefore, the following inconveniences may occur.

If a route for address A is already registered and another new WS is installed, there will be no problem if the address is properly managed to avoid duplication, but some users may install the address into the LAN without checking the address thoroughly. There is. In this case, the WS that was already in use and the W with the same address
There will be two S machines, and the above-mentioned table will be rewritten every time it is accessed.
performance becomes extremely poor. Moreover, since we do not know why the performance has deteriorated or who entered the wrong address, we end up spending a lot of time trying to find the cause.

[Means to solve the problem]

Once the WS address has been registered, it will be stored for a certain period of time (timer 1
(managed by ), then delete it from the table.

This timer has another timer 2, which counts a certain period of time after registration for each registered address. When an already registered WS address tries to register from another route,
Check whether this timer 2 is exchanging. If the route has been exported, delete the old route and register the new route. When timer 2 is not exchanging, rewriting is prohibited. Also, that frame is judged to be an invalid frame and is not passed through the bridge.This frame can only be sent within the same LAN, so a WS that later enters the LAN will immediately realize that it is abnormal. The WS that was noticed and registered earlier can freely use the LAN. It is natural to maintain the relationship of timer 1>>timer 2.

[Effect]

The address route registration table shows which LAN the received frame is connected to.
Used to refer to whether to send. timer 1
Address routes that have not been used for a long time are erased. Timer 2 is used to protect the address routing table in use from being erased due to an error. It usually takes 10 to 20 minutes to remove the WS that was being used from the route, connect it to another route, and start using it.

Timer 2 is set to a value of this order. By doing this, it is possible to prevent work from being interfered with by WSs that are connected by mistake.

【Example〕

Embodiment Φ of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 2 shows a diagram of a LAN system in which LANs 1 to 3 are connected by two bridges 4 and 5.

6 to 9 are WSs or host nodes connected to the respective LANs 1 to 3. Here, it will be explained as WS.

LANs 1 to 3 may be ring-type or bus-type, and do not depend on the topology. When data is sent from WSa to WS9, it is transferred only within LAN3. When transferring data from to WS6, press L.
A frame is sent from AN3 to LANI via bridge 5, and WS6 receives the frame.

When data is sent from a WS to a WS8, the sending wS sends it in the form of a frame with the source WS address, destination WS address, etc. added to the data.6 Figure 1 shows the internal block diagram of the bridge. There is. Frames received from the LANI enter the controller 23 from the receiving line 211 through the transmitting/receiving circuit 21 . 212 is a transmission line from the bridge to the LANI. 22, 211, 222
is a circuit that similarly controls the interface with the LAN2. 25 is an address route table, in which nothing is registered initially.

Below, examples of operation will be explained in order from the initial state. Assume that a frame is sent from WS8 to WS6.

This frame circulates around LAN3, bridge 5 and WS
9 receives the data, but the receiving address is WS6, so WS
9 is ignored. Bridge 5 looks at the source address and
Since this is my first address, I need to know the address of WS6 and that the route is LAN3.

Register the address in the route table 25 and send the frame to the LAN.
I, and start timer 1 and timer 2. LANI
The frame sent to is received by the WS 6 and the bridge 4. The receiving address of this frame is WS6, so WS
6 takes the uke. On the other hand, since bridge 4 has received the first WS8 frame, it registers that WS8 is on the LANI side from the perspective of bridge 4. Then bridge 4
sends a frame to LAN2, but since the recipient is absent, the frame is deleted.

Next, when WS7 sends data to WS8, similarly,
Bridge 4 registers that WS7 is on the LAN2 side, and the frame is addressed to WSB, so Bridge 4
sends the frame to LANI. When the bridge 5 also receives this frame, it registers that WS7 is on the LAN1 side, and the address route table 25 shows that WS8 is on the LAN3 side, so it transfers the frame to LAN3.
WS8 receives and receives the frame. In this way, each bridge uses its self-learning function to determine which address's W
Register which LAN S is connected to.

Addresses of WSs that are not used for a long time are erased from the address route table 25 of each bridge by timer 1. In addition, WS9 that was connected to LAN3 was connected to LAN2.
Even if you change the connection to
It is registered as being on the NQ side and can be used. However, WS9 and WS7 were mistakenly set to the same address.

When used simultaneously, even if the same address is attempted to be registered via different routes within a very short period of time at the bridge, it can be immediately rejected by monitoring the timer 24, and an abnormality can be immediately detected.

Also, when this phenomenon is detected, the bridge can store it in a special memory area as anomaly information. By reading bridge abnormality information from WS,
You can immediately know what kind of abnormality has occurred. That is, in this case, it can be immediately determined that WS7 and WS9 with the same address exist on LAN2 and LAN3.

〔Effect of the invention〕

According to the present invention, if a WS with the same address is mistakenly connected to the same LAN system, it can be immediately rejected and the abnormality can be immediately investigated. No more dropping.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram of a bridge, and FIG. 2 is a LAN system diagram of an embodiment of the present invention. 1-3...LAN, 4-5...Bridge. 6-9...Work stage 1 (WS). 21.22... Transmission/reception circuit, 23... Controller. 24...Timer, 25...Address route table. Easy! Snake second eye

Claims (1)

[Claims] In a node address management method in a bridge that connects one or more LANs, a route for a workstation address that has been once registered is set such that there is a request for registration of the same workstation address from another route. LA is characterized in that if the time has exceeded a certain period of time, the registration is rewritten, and if the period has not exceeded the certain period of time, the registration is not performed.
N-Bridge address management method. 2. In the address management system described in claim 1, if the registration rewriting is not performed, the sending station is provided with a response that indicates that the registration is a duplicate request. Characteristic LAN bridge address management method. 3. In the address management system according to claim 1 or 2, an already registered station address is accessed from another route before a certain period of time has elapsed.
An address management method for a LAN bridge, characterized by having means for storing that an address registration request has occurred.